Paper-sizing agent



Feb- 10, 1931- A. w. BURWELL PAPER SIZING AGENT Filed Deo. ll, 1926 Patented Feb." 1o, 1931 N UNET-Eo STATES.

PATENT CF1-ica Aivrmrn W. `:atrnWnL-L, or Nraeana raras, NEW Yoan, AssI'GNon 'ro'nLox CHEMICAL CORPORATION, or NEW Yoan, N. Y., A CORPORATION or NEW Yom:

PAPER-SIZING AGENT Application led December 11, 1926. Serial No. 154,201.

This invention relates to products particularly adapted for use as paper sizlng agents,

vto the process of making the Samb, and to pa-A pers sized with these products.

Papers commonly are sized by one of two methods; engine-sizing, wherein the sizing agent is added to the pulp in the beating engine and subsequently precipitated on the fibers in. an insoluble condition, and tubsizing, wherein the sizing operation is carried out on the paper-machine. AThe product ofthe present invention is more particularly adapted for use in the engine-swing operation.

Heretofore, the only agent widely used in the engine-sizing operation has been rosln or colophony, which is said to consist print, cipally of an acid body,abietic acid. An

aqueous solution of the sodium salt of this body,'obtainedI by dissolving rosin in a solution of an alkali, customarily is added to a# per pulp in the beating engine and the solu le lsodium salt converted to the insoluble aluminum salt of said-acid body by treatment .with a soluble aluminum salt.

The above described rosin size, although very widely used, is known to lack certain desirable characteristics and'topossess certain undesirable characteristics. For example, rosin size possesses imperfect water-repelling properties. Also, there is encountered great dificulty in retaining it in the paper stock in an amount greater than about 8% of the finished, sized paper, due to the fact thatthe insoluble rosin salt cannot be suiicently fixed or mordanted on the cellulose bers. This undesirable characteristic may artially account for the fact thatonl'y very limited quan'- tities of inert materials i. e., fillers) can be incorporated in the paper pulp, since it is believed that the fillers are retained therein only by virtue of the sizing agent.

One 'object of the present invention is to provide a sizing agent which shall possess the desirable characteristics of rosin size while avoiding the disadvantages above referred to. Among the advantageous characteristics to be desired are a more pronounced vater-repel# ling property, a more nearly perfect mordantability, and an ability to retain relatively agents. By

. possessin larger amoun'ts of inert materials (fillers) in occurring'` in petroleum oils, there may be l A obtained4 organic acid products, and that these may serve as starting materials for the production of valuable new paper sizing suitably controlling the conditions, it is possible to produce such agents characteristics that are varied within w1de limits.

The outstanding characteristic of these new agents is that they are capable of being almost perfectly retained or mordanted in the sheet, asi formed on thev wire 'of the paper-v machine, after precipitation in the form of an insoluble salt, in any proportion, in the pulp -by treatment with asuitable precipitant. For example, they may be'added to pulp in an vamount suiiicient to produce a nished paper containing' as as 50% by weight of said insolublel salt. c contradistinction thereto, it is known, as has been stated heretofore. that ordina rosin size is re-l tained with difliculty on t e cellulose fibers in amounts over 8% (based on the weight of the finished product). This characteristic pro erty of the new sizing agents renders possib e the retentioninthe sheet of larger proportions of inert materials (llers) than are possible when rosin size is used'. It has been found, also, that these new sizmg agents have, in many cases, as compare withl rosin size, enhanced waterproong properties, and that they produce papers which have from three to six times the strength of rosin-sized papers prepared lfrom the same pulp. Of` importance 1s the fact d ss that they may be manufactured 'at a cost materially lower than that of rosin size.

The process of making these products consists generally in the liquid-phase oxidation of hydrocarbons or mixtures thereof, includ! Although organic acid products may be derived from substantially all light and heavy distillates, I prefer to use as starting material a cheap petroleum distillate such as a 36 to Baum fuel oil distillate, obtainable from a crude petroleum having a paratline base, and having a distillation range substantially as follows:

Initial boiling point `260 C. distilled up to 321 C. 75% distilled up to 341 C. 87% distilled up to 360 C.

and transformed into an insoluble metal salt of the acid by treatmentwith the suitable inorganic salt of a metal; .for example, aluy minum sulfate or alum.

The invention will be described hereinafter by reference to the accompanying diagrammatic drawing which illustrates one form of apparatus suitable for carrying.,r out the oxidation process.

The oxidation -step proper takes place in an upright cylindrical reaction vessel or oxidizer 1, which may be, for example, about 5 feet -in diameter and about 16 to 18 feet in height. The oxidizer 1 may he made of any suitable material such as iron or steel and should be capable of withstanding pressures up to 350 pounds per square inch. Preferably` the oxidizer 1 should be made of or lined with material which is resistance to the corrosive action of the reaction mixture; for example, provided with an inner shell of aluminum or brick 2. The oxidizer is provided at a, point near its lower end with a tight coil 3` which serves asa heating or cooling coil as required. Suitable means, not illustrated, such as a jacket surrounding the oxidizer, also may be used to control the temperature of the oxidation reaction. At a point between the lower end of the oxidizer 1 and the tight coil 3 is an air spray pipe 4 connected by pipe line 5 to an air compressor 6. Air spray pipe 4 is so designed that air is ejected from it in the form of fine bubbles. 7, 8 and 9 are a valved hydrocarbon supply pipe, a valved liquid discharge pipe and a valved gas discharge pipe,

is a pressure gauge, and 11 is a thermometer.

12 is a force pump for circulating oil from the separating tank 13 to the oxidizer 1.

The valved discharge pipe 8 extends through the top of the oxidizer 1 to a point a. short distance viding an air space or air cushion over the body of oil 14 therein.

15 is a jacketed condenser connected to the oxidizer 1 by means of the valved liquid discharge pipe 8. 22 is a valved pipe for conveying liquid from the bottom of the condenser 15 to the top of the settling tank 13, While 21 is a pipe connect-ing the top of condenser 15 with the bottom of the absorbing tower 16. 17 is an oil supply tank connected to the top of t-he settling tank 13 by the valved supply pipe 18. 19 and 20 are pressure gauges and 23 and 24 are valved exit lines for leading oil" gaseousand liquid products from the absorbingr tower 16.

The process is carried out in the apparatus illustrated as follows:

A petroleum hydrocarbon oil, such as for example the hcreinbefore described 36 to 40 Baum fuel oil distillate, is charged into oxidizer 1, a small amount of an oxidizing catalyst such as a compound of manganese, copper or iron, say manganese oleate, amounting to about 0.1 percent of the weight of thc oil is added and the mixture heated upto a temperature in the neighborhoodof 120 C. or higher, preferably to about 1354410o C., and an oxidizing gas, preferably air, is supplied through the spray pipe 4. Gases are permitted to accumulate in the oxidizeruntil the desired pressure is reached, after which the pressure is maintained or regulated by controlling the discharge of gases through the valved gas discharge pipe 9. The pressure may vary considerably, say from 250 to 320 pounds per square inch. The preferred pressure will depend upon a number of conditions, including the temperature maintained, the kind of hydrocarbon mixture under treatment, the rate of air supply and, if oxygen-enriched air is used, upon the richness of the oxygen supply. It is preferred to carry out the oxidation process under such conditions that the reaction is substantially self-sustaining. In general, the reaction is self-sustaining at a temperature of about 135-140c C., and at a pressure of about 200-300 pounds per square inch, with the hydro carbon under treatment, although temperatures and pressures may vary between wide limits. Thus, lfor example. oxidation has been observed at a temperature as low as 100 C.; it is more rapid above 120 C., and the temperature may bevallowedfto rise to 155 C. with satisfactory results under some circumstances. 1 Therefore, while I prefer to carry out the oxidation process at a temperature at which the reaction rate is respectlvely. 10.

fairly rapid, say 135-140 C., it is to be understood that the invention includes the below the top, thereby proem loyinent of all suitable. temperatures at which oxidation takes place.

During the oxidizing treatment, as is stated above, gases collecting in the upper end ot oxidizer 1 are released through the Vpipe 9. These gases contain practically no oxygen, but do contain carbon dloxide, nitroi oil. The rate of flow through the oxidizer is so maintained that nevel' more than 10%, and preferably not more than i-5%, of the heavy organic acids are present in the overflowing mixture. This would be at about the rate su-ch that i'he whole amount of oil in the oxidizer is renewed once in 24 hours. Also, the volume of air passed through the oil naturally must be regulated to give the correct degree of oxidation. Deficiencies in the volume of oil circulating through the apparatus Amay be made up by adding, either continuously or intermittently, fresh raw material from an oil supply tank 17, through valved pipe line 18. i

Uncondensed products pass out of condenser into absorbing tower 16 4which tower is partially filled with broken limestone, where a part of the uncondensed products may be absorbed. Unabsorbed gases' pass out of tower 16 through pipe line 24, and condensate may be drawn from the bottom of said tower through the valved pipe line 23. f

The oxidation products present in the overflow from oxidizer 1, being heavier than the unoxidized oil and-insoluble therein, settlc to the botom of the separating tank 13 and may be drawn therefrom through the valved pipe linev26, leading'from'the bottom of said tank, into a still 27. These oxidation products have* been found to consist mainly ot organic'acids of relatively high molecular Weight,-comprising carboxylic and hydroxy-carboxylic-` acids-together with heavier ketones and other bodies.

The crude mixture of acidic oxidation products after having been separated from the unoxidized oil and only partly oxidized oil in the separating tank 13 and drawn into the still 27, is there purified by treatment with live steam. The temperature of the' or steam jacket (not shown). -During this heating operation water and ketones are distilled off. Then steam is bubbled through the mixture until all volatile bodies have been removed. Upon cooling the contents of the still, some heavy sludge may be sep-V arated out. This is carefully drawn ofi', andthen the purified organic oxygen-containing acids, or size acid, are Withdrawn into a suitable vessel for neutralization (not shown). Preferably the said size acid is neutralized by agitation with the required amount of caustic soda solution or soda ash solution, forming Water-soluble alkali metal soaps of the organic oxygen-containing acid. The Water-soluble alkali metal soap of the said size acid may be added to the pulp in the beating engine in much the same manner as ordinary rosin size. Upon addition ot the requisite amount of a suitable precipitant, as, for example,.alum or aluminum sulfate, it is caused to become fixed or mordanted on the cellulose fibers in almost any proportion. Preferably an excess of aluminum salt is used.

The sizing agents made according to the above described process are rather dark in color, butthe precipitated aluminum salts are comparatively light colored. The sizing agents may be bleached, if desired, according to the following procedure: An excess of the alkali solution is added to the purified size acid. and chlorine gas passed therethrough until the desired color is obtained. rl`his operation may be carried out either with or without heating. Any excess dist-illates containing little or no crystalline bodies (Wax) form the strongest papers, at some sacrifice in Water-repelling properties, and that these sizing agents which have been prepared from distillates containing much Wax and considerable quantitiesof unsaponifiable matter do not add ymaterially to the strength of the paper but do offer relatively very great water-repelling properties. I have found, further. that paraf'fiue wax may be oxidized so that 1020% of the mass is soluble in an aqueous solution of an .alkali toform an emulsiflable product which n'iay be incorporated in papers in the form of water-insolublc, unsaponifiable, bodies. in almost any proportions, for example in amounts up to 50% ofthe final Weight of the finished papers.

Although in the above description I have disclosed a continuous process for the prep- This application is a continuation in part' of my co-pending applications Serial No. 588,073, filed Sept. 13, 1922, and Serial No. 642.638, filed May 31, 1923.

What I claim is:

1. As a product. a material adapted for use as a paper 'sizing agent and consisting essentially of water-soluble alkali metalsalts of normally liquid water-insoluble, petroleum-insoluble` relatively7 high molecular weight aliphatic carboxylic and hydroxy-'can boxylic acids, said product being further characterized in that' it is capable of being retained in a paper inan amount up to 50% by Weight.

As a product, a material adapted for use as a paper sizing agent and consisting essentially of Water-soluble alkali metal salts of the normally7 liquid water-insoluble, petroleum-insoluble. relatively high molecular Weight aliphatic carboxylic and hydroxy-carboxylic acids produced by the protracted liquid-phase oxidation of petroleum hydrocarbon mixtures at elevated temperatures not in excess of about' 155 C. and at a pressure greater than atmospheric in the presence of an exciter of oxidation. said product being further characterized in that it is capable of being retained in a paper in an amount up t'o 50% by weight.

3. A sized paper, comprisingr a fibrous ce1- lulosic web and a sizingr material, said sized paper. being characterized in that it has a 1afreater Water-repelling capacity and a. greater strength than that possessed by a rosinsized paper containina the same amount of sizing` material and further characterized in that its sizing material consists essentially of water-insoluble metal salts of Water-insoluble petroleum-insoluble, relatively high molecular weight aliphatic carboxylic and hydroxy-carboxylic acids.

4. A sized paper lcomprising; a fibrous cellulosic web and a sizing material, said sized paper being characterized in that it has a y greater water-repelling capacity and a greater strength than that possessed by a rosin-sized paper containing the same amount of sizing;r material and further characterized in that its sizing material consists essentially of Waterinsoluble metal salts of the water-insoluble, petroleum-insoluble, relatively high molecular weight aliphatic carboxylic andhydroxycarboxylic acids produced by the protracted liquid-phase oxidation of petroleum hydrocarbon mixtures at elevated temperatures not in excess of about 155 C. and at a pressure greater than atmospheric in the presence of an exciter of oxidation.

In ytestimony whereof, I aiiix my si nature.

ARTHUR W. BUR ELL. 

